Fluorine-containing elastomers, especially perfluoroelastomers containing a tetrafluoroethylene (TFE) unit have excellent chemical resistance, solvent resistance, and heat resistance. Thus, they are widely used as, for example, sealants in severe environments in the aerospace field, the semiconductor equipment field, the chemical plant field, and the like.
Addition of filler to fluoroelastomers is a known technique to improve characteristics that sealants need to have.
In order to provide a semiconductor equipment sealant having heat resistance, low gas permeability, and stability even against plasma irradiation in an oxygen or CF4 atmosphere, and generating no dust, Patent Literature 1 proposes adding 1 to 50 parts by weight of silica and 1 to 10 parts by weight of an organic peroxide relative to 100 parts by weight of a fluoroelastomer.
In order to improve the plasma resistance and to reduce generation of particles after plasma irradiation, Patent Literature 2 proposes adding fine particles of aluminum oxide having an average particle size of not greater than 0.5 μm to a cross-linkable fluoroelastomer component.
In order to provide a white pigment-containing composition of a peroxide-vulcanizable fluoroelastomer having improved residual compression set, Patent Literature 3 proposes adding ultrafine white carbon particles used in the form of 4 to 5 wt % aqueous solution with a pH of 9 to 12 to a fluoroelastomer.
In order to provide a fluoroelastomer composition capable of maintaining heat resistance and processability in an environment involving direct plasma exposure, such as the inside of a dry etching device, having a small weight change against both fluorine plasma exposure and oxygen plasma exposure during a semiconductor manufacturing step, and generating no foreign substances (particles) in these treatments, Patent Literature 4 proposes adding, to a fluoroelastomer, at least one selected from the group consisting of isoindolinone pigments, quinacridone pigments, diketopyrrolopyrrole pigments, anthraquinone pigments, amine antioxidants, phenol antioxidants, sulfur antioxidants, and phosphorus antioxidants.
Patent Literature 5 discloses a filler which has a small weight change against both oxygen plasma irradiation and CF4 plasma irradiation and which is formed from a synthetic polymer compound containing an amide bond in the main chain or a synthetic polymer compound containing an imide bond. This literature also discloses blending of this filler to a cross-linkable elastomer.